The invention provides an unintermittent direct-current power supply, and belongs to the field of power supply devices. The unintermittent direct-current power supply is characterized by comprising an isolation transformer, a rectifying and filtering circuit, a converter, a constant-voltage charging module, a constant-current charging module, storage batteries, a switching circuit, a voltage sampling module, a current sampling module, a voltage boosting module and electric equipment, wherein the isolation transformer is respectively connected with the converter, the constant-voltage charging module and the constant-current charging module via a rectifying and filtering circuit; the converter is connected with the switching circuit; the switching circuit is connected with the electric equipment; the constant-voltage charging module and the constant-current charging module are respectively connected with the voltage sampling module and the current sampling module through the storage batteries; the storage batteries are connected with the voltage boosting module; and the voltage boosting module is connected with the switching circuit. By the combination of the various modules and switch circuits, the unintermittent direct-current power supply has the advantages that the precision of outputted current is high, ripple waves are small, and influences of a load on the outputted current are small. Moreover, the unintermittent direct-current power supply is simple in structure and is suitable to be popularized and used in a plurality of fields.